What was found
AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED DUE TO: SHORTLY AFTER ROTATION WE NOTICED AN ODOR. IMMEDIATELY AFTER THE ODOR WE RECEIVED A LAV SMOKE INDICATION, AND FLIGHT ATTADNENT CALLED AND REPORTED FOUL ODOR AND LAVATORY SMOKE DETECTOR GOING OFF IN FORWARD LAVATORY AS WELL, ODOR IS LIKE A BURNT FUEL AND EXHAUST SMELL. AIRCRAFT AIR INTERRUPTED BACK TO AND LANDED SAFELY AT ORD. ACCOMPLISHED WORKCARD 08L00021001 FOR SMOKE ODOR FUMES, PREFORMED PACK BURN TO REMOVE SMOKE.